Since early Windows releases, I have created a Startup On Hold program folder and Run On Hold registry branch to keep certain programs from loading. Recently, I was working on a project and I did not want my personal firewall, Zone Labs' ZoneAlarm, running during that time. (When the ZoneAlarm service detects an Internet access attempt from a new program, zonealarm.exe provides a pop-up dialog box in which you must approve or reject the request for access.) So, I moved zonealarm.exe out of my Windows Startup folder and into my Startup On Hold folder and rebooted.
Several days after I moved zonealarm.exe into my Startup On Hold folder, I decided to upgrade from Microsoft Office XP to Office 2003. At first, the upgrade appeared to go well, but then some problems began to surface. The first problem I encountered is that none of the programs could access the Internet to perform their product registrations. I had to do the activations the hard way—over the phone. After I finished all the upgrades, I discovered that Microsoft Outlook 2003 was giving me all kinds of connection errors. I spent over an hour going over my email settings, creating new accounts, and performing other fix-it attempts. I then discovered that couldn't perform any product updates from with Microsoft Word, Microsoft Excel, or any of the other Office programs. However, when I ran Microsoft Internet Explorer (IE), I did not encounter any problems.
I decided to call Microsoft Product Support Services (PSS). The PSS technician suggested that I run Windows XP's msconfig.exe, select the Services tab, then enable the Hide all Microsoft Services option to see what third-party services were running. The PSS technician's suggestion was right on target. I saw that the TrueVector Internet Monitor service was enabled. I immediately thought, "That is ZoneAlarm! How can this be? I removed zonealarm.exe from the Startup group."
Then it hit me. I apparently did not disable ZoneAlarm's underlying function of blocking new program access. The ZoneAlarm TrueVector service was still loaded and blocking any new executable. My disabling of zonealarm.exe did nothing more than keep me from seeing the pop-up dialog box.
This situation taught me an important lesson when using personal firewalls (or other programs for that matter): Do not forget that these programs can have UI components that, when disabled, might not terminate the underlying processes.